Reversible jet pump



. g 1967 T. R. KINNEY REVERSIBLE JET PUMP Filed Oct. 19, 1965 INVENTOR THURLOW R. KINNEY BY M 7 ATTORNEY United States Patent 3,338,169 REVERSIBLE JET PUMP Thur-low R. Kinney, 105 Fillmore Ave., Endicott, N. 13760 Filed Oct. 19, 1965, Ser. No. 497,930 4 Claims. (Cl. 10394) ABSTRACT OF THE DISCLOSURE The invention is a rotary jet pump having features of economy and simplicity characterized 'by a single casting for gearbox and pump and by twin, contra-rotative rotor stators mounted in a pump chamber by means of bearing seals. The rotor stators form the path for the water stream. The rotor stators and bearing seals require no close fit with the chamber walls of the pump housing.

This invention relates to fluid propulsion, and more particularly to a jet propulsion unit for watercraft.

The invention takes cognizance of the various requirements of watercraft propulsion, including economy, dependability and safety. It includes a rapidly reversible centrifugal pump jet propulsion unit which can operate with ordinary outboard motors as well as with more complex power units.

Characteristics of the invention pulsion unit is essentially a pump which draws intake.

Water into a chamber, adds power to increase the water velocity, and expels the high-velocity water through a more or less constricted jet aimed oppositely to the direction of craft motion. Various forms of inboard-powered rotary driven pumps have been used successfully. Outboard rotary driven pumps, however, have not been popularized.

Objects An object of'the invention is to provide a simple, dependable and economical outboard rotary driven jet propulsion unit for watercraft.

Another object of the invention is to provide a rapidly reversible jet pump.

Features of the invention A feature of the invention is the positioning of two identical rotor stators on concentric shafts in such fashion that one rotates while the other remains stationary, within a sealed chamber having forward and reverse jet nozzles.

Another feature of the invention is an arrangement of clutches and gears with a reversible jet pump of two identical rotor stators arranged on rotatable concentric shafts to provide rotative power selectively to one rotor stator and to stop rotation of the other rotor stator.

Another feature of the invention is the arrangement of seals with two identical rotor stators on concentric shafts arranged to be alternatively driven in opposite directions or held stationary so that the rotating rotor stator serves as rotor while the stationary rotor stator serves as stator, the rotor stators being sealed and positioned with respect to jet nozzles so that the stator provides high velocity water to its respective jet nozzle.

3,338,169 Patented Aug. 29, 1967 Advantages The advantage of the invention is its appropriateness for small watercraft in that it is safe, economical, simple and easily adaptable to outboard power units.

Another advantage of the invention is its interchangeability with a screw propeller when used with outboard power units.

Other objects, features and advatanges of the invention will become apparent from the description of the invention contained in the following detailed portion of the specification, in the accompanying drawing and in the claims.

Drawing The figure is a side view of the invention, with certain housings broken away and with significant portions shown in vertical section.

Summary of the invention The invention is a reversible jet pump which is useful as a propulsion unit for watercraft. It is made up of two rotor stators 1 and 2 which may be identical. The rotor stators are drilled to provide passageways for fluid; when operated as a rotor, the rotor stator takes in fluid at the ends of the passageways nearest its axis of rotation and expels it under centrifugal force at the ends of the passageways farthest from the axis of rotation. The rotor stators are mounted for individual rotation on concentric shafts 3, 4, which are arranged with gears and clutches in gearbox 5 for non-coincident operation. Rotor stators 1, 2 are mounted in pump housing 6, in a chamber sealed by bearing seals 7, 8.

Forward propulsion takes place when the mechanism in gearbox 5-rotates shaft 3 while holding shaft 4 stationary. Rotor stator 1 rotates, drawing water through reverse nozzle 9 into its passageways and expelling the water into the chamber of pump housing 6. Water pressure built up in the chamber is relieved through the passageways of rotor stator 2, which at this time is stationary and acts as stator. Water flowing out of rotor stator 2 passes out of forward jet nozzle 10, providing forward thrust.

Reverse propulsion takes place when rotor stator 2 is rotated and rotor stator 1 is held stationary. Overrunning clutches are used to hold the rotor stator currently acting as stator.

Details of invention Figure shows the invention as a Watercraft propulsion unit. Forward rotor-reverse stator 1 and reverse rotorforward stator 2 are mounted respectively on concentric forward shaft 3 and reverse shaft 4. The forward shaft is rotated while the reverse shaft is held stationary, for forward propulsion. Gearbox 5 provides the selective rotation of shafts 3 and 4. The reverse shaft 4 is similarly rotatable While forward shaft 3 is held stationary, for reverse propulsion. Rotor stators 1 and 2 are sealed within pump housing 6 by hearing seals 7, 8, so that fluid flow is from reverse jet nozzle 9 or forward jet nozzle 10 or conversely.

The entire propulsion unit may be powered by an outboard motor (not shown) mounted on a watercraft rear transom 11. The motor provides rotation to shaft 12 and gear 13. Gear 13 selectively provides power to forward shaft 3 via gear 14 or to reverse shaft 4 via gear 15. There is no danger of damage to metal parts if both the forward and reverse shafts should through malfunction be connected to the drive shaft at the same time; both rotor stators would rotate, canceling the flow.

Proper operation however requires that the reverse shaft be stationary when the forward shaft is rotating and vice versa. Overrunning clutches 16, 17 serve to prevent rotation of the shafts in the direction opposite their normal drive direction.

A honeycomb bafile may be advantageous between the two rotor stators, although for small size propulsion units it is not preferred.

The gearbox has a suitable number of hearings to provide rattle-free rotation to the forward shaft 3 and to the reverse shaft 4. Forward shaft 3 may conveniently be supported on bearings on reverse shaft 4. Reverse shaft 4 is supported by a bearing 20 at the forward end and by hearing seal 8 and rotor stator 2 at the rear. Gears 14 and 15 make continuous contact with drive gear 13 and rotate continuously and freely on their respective shafts. Electric clutches 18 and 19, respectively keyed to forward shaft 3 and reverse shaft 4, are arranged to selectively connect the drive shaft 12 to the forward shaft 3 or the reverse shaft 4, depending upon which clutch is energized by the operator of the watercraft.

Manually operated forward-reverse shifting by standard power transmission techniques is also effective. For manual shift units, it is convenient to have a reverse input cutout 21 connected to the shift lever, so that the forward intake can be taken through a larger port than offered by the reverse nozzle.

Since the propulsion unit mounts flush with the keel of the watercraft, it is safe from marine obstacles which might break a propeller blade. Clogging by marine growth is minimized by the placement of the intake ports (jet nozzles), but if clogging shoul occur its removal is simple. The offending matter may be quickly expelled simply by reversing the flow of water through the propulsion unit.

While the propulsion unit has been shown and described in the preferred embodiment of a watercraft propulsion unit, it is obvious that it is subject to the foregoing and other changes in form and details, and that one skilled in the art could apply it to stationary pumping tasks or other uses without departing from the spirit or enlarging the scope of the invention.

What is claimed is:

1. A jet propulsion unit for watercraft, having (a) a first rotor stator having fluid carrying channels arranged for centrifugal action at one end;

(b) a second rotor stator having fluid carrying channels arranged for centrifugal action at one end;

, (c) a pump housing enclosing a pump chamber and having two jet nozzles arranged each to conduct fluid in series with said pump chamber;

(d) means mounting contra-rotative concentric first and second shafts within said pump housing so as to extend through said pump chamber, said means including supports at both ends of said shafts;

(e) means mounting said first rotor stator to said first shaft and means mounting said second rotor stator to said second shaft in driving relationship;

(f) characterized by a first bearing seal sealing said first rotor stator within said pump housing with its centrifugal end inside said pump chamber;

(g) a second bearing seal sealing said second rotor stator within said pump housing with its centrifugal end inside said pump chamber;

(h) means to provide rotative power selectively to said contra-rotative first and second concentric shafts; and

(i) first and second overrunning clutches respectively mounted on said first and second contra-rotative concentric shafts to inhibit non-contra-rotative movement of said first and second shafts.

2. A jet propulsion unit according to claim 1, wherein said pump housing (0) and said means to provide rotative power (h) include a single casting for gearbox and pump housing.

3. A jet propulsion unit according to claim 1, wherein said pump housing (c) is detachable from said means to provide rotative power (h).

4. A jet propulsion unit according to claim 1, further characterized by means to alter the configuration of said pump housing (c) jet nozzles, including means for moving a reverse input cutout which configures the forward intake larger than the reverse nozzle.

References Cited UNITED STATES PATENTS 3,111,108 11/ 1963 Trotter -221 3,112,610 12/1963 Jerger 230-123 3,174,454 3/1965 Kenefick 60221 3,187,708 6/1965 Fox 1l512 3,225,537 12/1965 Parsons 230123 3,249,058 5/1966 Parsons 60-221 3,250,069 5/1966 Rhoda 60221 DONLEY J. STOCKING, Primary Examiner.

HENRY F. RADUAZO, Examiner. 

1. A JET PROPULSION UNIT FOR WATERCRAFT, HAVING (A) A FIRST ROTOR STATOR HAVING FLUID CARRYING CHANNELS ARRANGED FOR CENTRIFUGAL ACTION AT ONE END; (B) A SECOND ROTOR STATOR HAVING FLUID CARRYING CHANNELS ARRANGED FOR CENTRIFUGAL ACTION AT ONE END; (C) A PUMP HOUSING ENCLOSING A PUMP CHAMBER AND HAVING TWO JET NOZZLES ARRANGED EACH TO CONDUIT FLUID IN SERIES WITH SAID PUMP CHAMBER; (D) MEANS MOUNTING CONTRA-ROTATIVE CONCENTRIC FIRST AND SECOND SHAFTS WITHIN SAID PUMP HOUSING SO AS TO EXTEND THROUGH SAID PUMP CHAMBER, SAID MEANS INCLUDING SUPPORTS AT BOTH ENDS OF SAID SHAFTS; (E) MEANS MOUNTING SAID FIRST ROTOR STATOR TO SAID FIRST SHAFT AND MEANS MOUNTING SAID SECOND ROTOR STATOR TO SAID SECOND SHAFT IN DRIVING RELATIONSHIP; (F) CHARACTERIZED BY A FIRST BEARING SEAL SEALING SAID FIRST ROTOR STATOR WITHIN SAID PUMP HOUSING WITH ITS CENTRIFUGAL END INSIDE SAID PUMP CHAMBER; (G) A SECOND BEARING SEAL SEALING SAID SECOND ROTOR STATOR WITHIN SAID PUMP HOUSING WITH ITS CENTRIFUGAL END INSIDE SAID PUMP CHAMBER; (H) MEANS TO PROVIDE ROTATIVE POWER SELECTIVELY TO SAID CONTRA-ROTATIVE FIRST AND SECOND CONCENTRIC SHAFTS; AND (I) FIRST AND SECOND OVERRUNNING CLUTCHES RESPECTIVELY MOUNTED ON SAID FIRST AND SECOND CONTRA-ROTATIVE CONCENTRIC SHAFTS TO INHIBIT NON-CONTRA-ROTATIVE MOVEMENT OF SAID FIRST AND SECOND SHAFTS. 